Detroit DD13 GHG14 (2014-16) Fault Code: SPN 556 FMI 9 (CPC) J1939 RC Message from Transmission Retarder Missing

NOTE: Fault will set during transmission module reprogramming. If fault occurs while programming, clear code and release vehicle.

NOTE: It is normal for this code to appear if you’ve programmed the Eaton Transmission. Just clear the code and release vehicle.

PROBABLE CAUSES:
1. If any codes related to battery voltage are present, fix those first.
2. If 625-9 present, troubleshoot that instead.
3. If any engine modules have been programmed recently, check configuration.
4. Another computer module on the truck (ABS, transmission, cab, etc…) has a failure that is causing this.